The present invention relates to a method of decontaminating soil, and more specifically, to a method of decontaminating soil, porous rock and the like contaminated by hydrocarbon, petroleum based and organic compounds by treatment with an emulsifying and volatilizing agent.
Concern for the environmental stability of the earth and its fragile ecosystems has altered many aspects of commerce. Recycling of glass and metal containers, municipal sewage treatment and energy conservation are primarily products of the last four decades. Since the passage of the Clean Air Act (CAA) in 1970, this bill and subsequent legislation has empowered the government to act to control and reduce environmental pollution from motor vehicles, factories, municipalities and other commercial activities.
One of the underlying ecological precepts of the public and the governmental environmental programs as well, is the very real limits on both the quantities of natural resources that are available and the extent to which life supporting systems such as lakes and waterways, soil and plant life may be abused without having serious and long lasting effects on directly or remotely related environmental systems.
For example, at one time no questions were asked when hydrocarbon fuels, petroleum distillates and organic chemicals were spilled or discharged into waterways or the soil. Later, questions were raised as to whether the discharge of such materials into waterways, aquifers, or soil might have long term deleterious effects. Now, the question is unequivocally answered in the affirmative. Accordingly, efforts are underway not only to eliminate such occurrences, but to clean and clear areas where such contamination has occurred in the past.
Treatment of such hydrocarbon and petroleum distillate contaminated soil presents significant problems. In light of these problems, one of the most common treatments has been simply to move such soil or similar material such as porous rock to a landfill where it will be perpetually isolated from the environment. Such perpetual isolation frequently lasts only so long as steel drums take to rust or a clay dike takes to develop leaks. Then, the material is moved to another perpetual storage area.
Methods have been proposed in the patent art for isolation of contaminants and detoxification of soil and the like. For example, U.S. Pat. No. 4,645,382 teaches a method of isolating and containing soil contaminants. The method disclosed therein comprehends the installation of a layer of sealing material such as alkali silicate to form an impermeable barrier which isolates the contaminated soil region.
U.S. Pat. No. 4,839,061 teaches a method and apparatus for treating hazardous material spills. Here, an unspecified chemical reagent is utilized in a mechanized boom having a pick up head with sensors, spray jets and suction inlets. The apparatus is intended to speed treatment and collection of spills of hazardous material.
U.S. Pat. No. 4,913,586 teaches another method for treating soil contaminated by pollutants such as petroleum and hydrocarbon liquid. The patent is directed to a material which protectively coats each particle of contaminated soil to inhibit the volatilization or release of the toxic components from the soil particles.
From the foregoing, it is apparent that while processes for dealing with hydrocarbon and organic contaminants in soil exist, none deal with the actual reclamation of the soil, that is, returning it to its original, pristine, unspoiled state by removing the hydrocarbon contaminants such that the soil may again be used as clean, uncontaminated soil. The present invention relates to such a process.